Indeed, it isn't even a proper W12 (that would be 3 inline 4s); a normal V12 is balanced because it combines two in itself super balanced inline 6s. The W12 was always a compromise between reusing many existing VR6 parts and packaging (it lives ahead of the front axle in all but the new Continental), and as a result is not the best 12 cylinder out there, actually quite the opposite.